2mm Scale Picture Gallery shows what is possible in ( almost ) N scale and, most interesting, information on etching brass and scratchbuilding a small lathe.
Railroad Line Forums is a very active community of great modeles showcasing their projects and models.
Techniques adaptable for model railroading can be found at IPMSStockholm.org - Webzine about plastic scale models, model building, modelling news, techniques and reference maintained by IPMS Stockholm of Sweden.